But not every watering hole is open to the public, and not everyone is safe. As hot residents cool themselves down in public fountains, city officials are struggling to keep their residents out of unsafe waters.

In upstate New York, where temperatures hit 95 degrees this past week, the Clinton Square fountain located in downtown Syracuse has seemingly turned into an outdoor water park. That's despite the police's efforts to quell the frenzy. Swimming, wading and entering the fountain has been prohibited since its opening a decade ago.

"It's hot!" Syracuse resident Karen Larue, a single mother who brought her 8-month-old daughter, Juliana, to Clinton Square, said. "I don't really like any of the public pools. They're disgusting and too crowded. But the fountain is free, filtered and convenient."

The fountain, which sits in the middle of an open square of benches and tables where locals often play a game of chess or catch up with friends, runs about the length of an Olympic-sized pool and stands about as deep as an average kiddie pool.

Even so, says Commissioner Patrick Driscoll of the Syracuse Parks and Recreation Department, "It was not designed as a pool."

But Larue wasn't concerned. "If we can swim in a lake why can't we swim in a fountain? The water's moving so you've got to think it's filtered. So that's good enough for me," she said. "Two [cops] walked by here earlier for about an hour and they didn't say anything. So where are they? No one's here to tell us no."

Safety Concerns at Washington, D.C. Fountain

In Washington D.C., the fountain at the Navy Memorial presents a sanitation issue.

"We have homeless people wash their clothes in the fountain," Taylor Kiland, vice president of marketing and communications for the Navy Memorial, said. "They also 'release' themselves in the fountain. I've heard of this once or twice."

Kiland says that while people do not often enter the narrow and triangular-shaped fountains that sit at the center of the Memorial Plaza, it is common for visitors to dip their hands in the water during their lunch breaks.

"Everybody has done it. It's just too irresistible," she said.

New Yorkers Flock to the Fountain at Washington Square Park

New York City, which has more than 50 decorative fountains in public parks -- with bathing and cleaning clothing prohibited -- find one of their fountains irresistible too. In an if-you-can't-beat-'em-join-'em spirit, the city recognizes that people in Greenwich Village will play inside the fountain at Washington Square Park.

"At this fountain we maintain a low volume of water and keep it shallow to ensure safety," NYC Parks spokesperson Vickie Karp wrote in an e-mail to ABCNews.com. "This fountain was equipped with a bromine filtration system. Bromine is an alternative to chlorine that also kills bacteria and harmful contaminants but holds up better in sunlight and has less of a chemical odor than chlorine."

New York City's fountains, Karp went on to write, are "equipped with filtration systems and disinfection systems to keep them clean and safe."